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In this contribution, the evolution of the Ladakh magmatic arc encompassing ca 160 Ma history from subduction initiation to intra-oceanic arc collision to final continent-continent collision is summarized. The observed compositional variation in Ladakh magmatic arc reflects directional maturity from mafic magmatism towards south to more acidic magmatism towards north, and therefore indicating northward dipping subduction. Based on the ca 160 Ma Neo-Tethys geodynamic reconstruction, the evolution of the Ladakh magmatism can be summarized into three distinct time periods; (i) from 160 to 80 Ma, representing intra-oceanic island arc (IOIA) complex dominantly of mafic magmatism, (ii) from 80 to 50 Ma, the magmatism shifts to felsic composition (involving Indian continental margin) in the form of Kohistan-Ladakh batholith and (iii) from 35 to 18 Ma, the magmatism occurred in the form of post-collisional dykes. We also support the double collision model of Ahmad et al. (2008), according to which the first collision occurred between IOIA complex (including Kohistan-Ladakh batholith) with southern margin of Asia during mid-Cretaceous to late-Cretaceous along Shyok Suture Zone (SSZ). Finally, the accreted IOIA and Asian plate margin collided with the northern margin of Indian plate during Late Eocene ∼40 Ma along the Indus Suture Zone (ISZ). [ABSTRACT FROM AUTHOR]

This article reports the existence of subduction-related tholeiitic, normal mid-ocean ridge basalt (N-MORB)-type mafic intrusives emplaced within the Sapi-Shergol ophiolitic mélange of the Indus Suture Zone, western Ladakh. The Shergol mafic intrusives show Fe enrichment with basalt to basaltic-andesite composition. Based on their mineralogy and textures, these mafic rocks can be identified as fine- to medium-grained gabbros that have undergone greenschist-grade metamorphism. These rocks have N-MORB-type geochemical characteristics, exhibiting nearly flat to depleted light rare earth element patterns ( (La / Sm) N = 0.66 – 1.05). Petrogenetic modeling suggests <20% partial melting of a depleted MORB-type mantle source, within the spinel peridotite stability. The presence of slightly negative anomalies of high field strength elements like Nb, Zr, and Ti in multielement patterns reflect the influence of subduction zone magmatism. The presence of low-Ti clinopyroxene (En38–50Fe11–25Wo31–43; enstatite-ferrosilite-wollastonite), Ca-rich plagioclase (An2–36; andesine), and pargasitic amphibole also reflects their subduction-related depleted-mantle origin. The MORB–island arc tholeiite signature displayed by the Shergol gabbros intrusive in Shergol peridotites reflect their generation in a mantle wedge associated with the Early Cretaceous intraoceanic subduction within the Neo-Tethys Ocean. They are similar to Spongtang ophiolite gabbros intrusive in the Spongtang ophiolite mantle peridotites from south Ladakh, ophiolitic mélange gabbros from southern Tibet, and Muslim Bagh ophiolite gabbros from Pakistan. Based on this study, we offer a geodynamic model suggesting that the Sapi-Shergol ophiolitic slice was intruded by mafic intrusive rocks that represent the relict of the intraoceanic substratum of the Cretaceous Dras arc complex. [ABSTRACT FROM AUTHOR]

The authors discuss the dextral transpression and late-Eocene magmatism in the trans-Himalayan Ladakh Batholin in North India and the tectono-magmatic evolution of the Indo-Eurasian collisional arc. The authors say that Ladakh Batholin is significant in granitoid chemistry and tectonic processes, such as continental collision.They tell that the Indus Molasse that was deposited after the exhumation of the batholin underwent deformation to produce of folds in the matrix and clasts of molasse.